Open top test tube and sample containers will encounter challenges to work effectively in the weightless or microgravity environment found on a space station or on a spacecraft. The liquid, once placed in the vessel, will cling to the bottom due to capillary forces regardless of the container orientation, making it problematic for extracting the liquid. Additionally, small movements of the test tube and sample containers will cause the liquid to spill or float free from the vessel's open top due to capillary forces being weaker than the inertial forces resulting from vessel motion. These two facts make current art in containers impractical in a weightless environment.
Current containers and liquid handling techniques have limitations, particularly when dealing in a weightless or microgravity environment and handling small liquid volumes in a highly accurate manner suitable for laboratory testing.